syntrophy

In biology, syntrophy, syntrophism, or cross-feeding () is the cooperative interaction between at least two microbial species to degrade a single substrate. This type of biological interaction typically involves the transfer of one or more metabolic intermediates between two or more metabolically diverse microbial species living in close proximity to each other. Thus, syntrophy can be considered an obligatory interdependency and a mutualistic metabolism between different microbial species, wherein the growth of one partner depends on the nutrients, growth factors, or substrates provided by the other(s).

== Microbial syntrophy == Syntrophy is often used synonymously for mutualistic symbiosis especially between at least two different bacterial species. Syntrophy differs from symbiosis in a way that syntrophic relationship is primarily based on closely linked metabolic interactions to maintain thermodynamically favorable lifestyle in a given environment. Syntrophy plays an important role in a large number of microbial processes especially in oxygen limited environments, methanogenic environments and anaerobic systems. In anoxic or methanogenic environments such as wetlands, swamps, paddy fields, landfills, digestive tract of ruminants, and anerobic digesters syntrophy is employed to overcome the energy constraints as the reactions in these environments proceed close to thermodynamic equilibrium.